Ignition Delay Times of Composite Solid Propellants Using Novel Nano-Additive Catalysts

The ignition delay times tign of propellants provide insight for the fundamental understanding of the ignition process. This study demonstrated a refined method to measure the tign of ammonium-perchlorate-based propellants at pressures between 3.5 and 15.5 MPa. Both aluminized and nonaluminized ammonium perchlorate/hydroxyl-terminated polybutadiene composite propellants were studied with and without metal oxide nanoparticle catalysts. A CO2 laser was used to obtain quantifiable and reliable ignition times over a 30–100 W power range. The tign results were compared to literature values for similar power fluxes at comparable pressures and to a simple ignition model based on heat conduction. Catalytic additives were seen to modify the tign, depending primarily on whether they impact the lower- or higher-temperature decomposition of ammonium perchlorate. Examining the effects of in situ titania nanoparticles on the ignition delay times led to the conclusion that the nano-additives only altered the ignition be...